Selective key for radio systems



Dec. 11, 1928 1,695,178

- E. E. CLEMENT SELECTIVE KEY FOR RADIO SYSTEMS Original F l F 20, 19253 Sheets-Sheet 1 Dec 11, 1928. 1,695,178

E. E. CLEMENT SELECTIVE KEY FOR RADIO SYSTEMS Original le Fe 20, 1925 3Sheets-Sheet 2 f fi ""0 lMvom/czz 126 11; J20 62 C 450 q 4- 3 as w L 3164 1 I "I 125 I 122/ Patented Dec. 11, 1928.

UNlTED STATES 1,695,178. PATENT OFFICE.

EDWARD E. cmmnn'r, or WASHINGTON, Drs'rnrcr or COLUMBIA, assreno'n 'roEDWARD r. COLLADAY, or WASHINGTON, DISTRICT or COLUMBIA.

SELECTIVE KEY FOR RADIO SYSTEMS.

Original application filed February 20, 1925, Serial No, 10,533. Dividedand this application filed August 1, 1925.

My invention relates to radio broadcast distributing systems, and thepresent applica: tion is a division of my prior co nding applicationSerial No. 10,533, filed ebruary 20,

6 1925, now Patent No. 1,672,373.

The object of the present invention is to simplify and improve theselective apparatus at a subscribers station, and in particular toprovide a combined switch and signal key for controllin the centraloflice line connection and selection of program, and also the localcircuit connections of the subscribers receivers.

I attain my objects by connecting a loud speaker to the coils of atelephone and provide a locking ke with variable plunger movement towork t e circuit closin contacts.

My invention is illustrated in t e accompanying drawings, in. which:Figs. 1 and 2 illustrate,diagrammatically,

the telephone exchange portion, and broadcast distributing portion,respectively, of a combined telephone exchange and broadcastdistributing s stem.

Fig. 3 is a iagram of a preferred form of subscribers apparatus.

Fig. 4 is a side view, partly in section, of the subscribers controlapparatus of Fig. 3.

Fig. 5 is a modified side view, partly in sec- 80 tion of thesubscribers control apparatus of Fig 3.

In Fig. 2, is shown diagrammatically the ar rangement of switching aparatus especially adaptable to use with the orm of subscriber sapparatus shown in Fig. 3. In the switching arrangement of Fig. 2 thesubscribers line terminal multiples 1 2, 3 and 4 extend from thetelephone switchboard circuits of Fig. 1. The multiples 12 terminate ina jack switch 40 119, arranged to extend the connectionthrough contacts120 and 121 to conductors 122 and 123 leading to the common battery Bthrough the secondary windings of the repeating coils 124 and 125 andsleeve relay 42 in series. The

signaling conductor 4 terminates at one terminal of the signaling lamp126, the other terminal of which is grounded, while the test con- Iductor 3 is arranged to be connected through a normally open contact 127of the sleeve relay so 42 to a characteristic busy tone test device 128,

meter controlled apparatus 129 and the ungrounded side of battery B. Asin Fig. 2, the subscriber is provided with an individual or line tube 37whose output circuit is arranged Serial N0. 47,549.

to include the primary windings of the repeatmg coils 124-4125 and whoseinput circult is arranged to be connected through contacts 130131 of thesleeve relay42 to the brushes or wiper contacts of selector switch S.The ack switch 120 is operated by a dummy plu 132 which upon insertionin the ]&Ck closes t e contacts 120-121 and 123, the closure of thecontacts 120121 effecting an extension of the line multiples 1-2 aspreviously described, while closure of the contact 123 extends thesignal conductor4through to conductor 134 connected through a normallyclosed contact 135 of the rela 42 to the battery B. The selector switchcontains bank contacts 88'--8 connected to separate 7 pairs of bus wires136 (carrying No. 1 program), 137 (carrying N0. 2 program), an 138(carrying No. 0 or announcements). The switch S does not need to berestored to zero, and may be left always in the last position to 7 whichit has been moved, since the wires 139140 leading to the wiper arms ofthe switch are cut off at the relay contacts 130-131 when the apparatusis in disuse. The No. 1 and 2 program busses are connected to the outputcircuits of broadcast relay receivers 141 and 142, respectively, and theannouncement bus wires 138 are connected to a local distributingapparatus or amplifier AS with a microphone Mf. This position orequipment on the radio switchboard corresponds to the informationoperators position on a telephone switchboard.

The operation of the system using the subscribers apparatus of Fig. 3with the central ofiice circuitsof Figs. 1 and 2 is as follows: Thesubscriber desiring broadcast service calls as before, by making shortclosures of his line with the starting button after first pushing itdown beyond the lock- 5 ing position. These short closures flash boththe telephone switchboard lamp L (Fig. 1) and the broadcast switchboardlamp 126 (Fig. 2). The operator at the broadcast service boardperceiving the flash of the 100 lamp 126 knows that the subscriber wantsbroadcast service and responds by inserting the dummy plug 132 in the'ack switch which extends the subscriber s line multiples 12 throughcontacts 120-121 to the con- 1 5 ductors 122-123, thereby completing thesubscribers line circuit through the secondary windings of the repeatingcoils 124--125 which circuit may be traced from battery B (Fig. 2)through the circuit elements, secondary winding of repeating coils 124,122, 120, 1, into Figs. 1, 69, into 3, I, 118,- 10a 110-111,114, 117,70, into Figs. 2, 121, 123, 42, and through secondary winding ofrepeating coil 125 back to battery B. As this circuit includes windingsof the relay 42 this relay is energized closing the input circuit of thesubscribers line tube 37 onto the wipers of the switch S by way ofcontacts 130-131 and conductors 139-140 and as the output circuit of thetube 37 ineludes primary windings of the repeating coils 124125 thesubscriber now hears on his loud speaker 101 (Fig. 3) one of thebroadcast programs or the announcements from the announcer bus accordingto the position of the switch S (Fig. 2). If it is one of the programsthat he receives and he desires to select some particular item, he canby means of the button 105 (Fi 3) propel the wipers of the switch Saround step by step until they come in contact with the bank contacts 8connected to the announcers bus 138, and by listening, he will hear acontinuous announcemeritv of the items then u on the busses, the itemsto follow, the num ers or call letters of the stations from which thesaid items are being sent, and any other interestin informationconnected with the same. aving ascertained a whole list of itemsavailable for the moment with the number of the program busses on whichthey are to be found, the subscriber may by operation of his button 105operate the switch to start from the announcer bus as zero and steparound to the desired bus such as 137, 136, etc.

When the subscriber desires to discontinue the broadcast service, heactuates the off or release button 106 to release the button 105 andrestores his receiving apparatus and line circuit to the open or normalcondition whereupon the sleeve relay 42 (Fig. 2) becomes deenergizedopening the input circuit of the tube 37 at contacts 130-131 andenergizing the signal lamp 126 in a circuit which may be traced frombattery B (Fig. 4) through circuit elements 135, 134, 133, 126 to groundand back to battery B. The broadcast service operator perceiving thesteady glow of the lamp 126 knows that the subscriber desiresdisconnection and thereupon withdraws the plug 132 which opens thecontacts 120121-133 of the jack switch 119. The opening of the contact133 extinguishes the lamp 126 while the opening of contacts 120121 opensthe connection across the subscribers line multiple 12, thus restoringall circuits to normal.

Referring now to Fig. 4 which shows the subscribers key 102 in detail,this key comprises a mounting plate 141 carrying a downward extension142 at the lower end of which is mounted the contact supporting igs. 1,2 into" base 143. 105 is the starting button which has bearing in themounting plate 141 and base 143 through the upper stem 144 and the lowerstem 145, respectively. Mounted betwen the upper and lower stems 144145is a cam member 146 having a cam surface 147 arranged, upon downwardmovement ofthe cam member, to move the contact spring 109 intoengagement with the contact spring 110 and the latter into engagementwith the contact spring 111. Another cam surface 148 on the right handside of the member 146 is arranged, upon downward movement, to move thecontact spring member 149 to the right and disengage the contact 114.The right hand side of the member 146 is made straight or parallel inits direction of movement, above the cam surface 147 so that when themember 146 is moved downwardly to operate the spring contacts 109, etc.,a continuous downward movement. will maintain the contacts closed. Aswill be seen from the drawing, the cam surface 148 is placed above thecam surface 147 while the cam engaging portions of the springs 109 and149 are at substantially the same level, so that upon the first portionof the downward movement of the member 146 the contact springs109-110-111 will be actuated, and upon further downward movement thespring 149 will be actuated. Below the mounting plate 141 near the upperportion of the cam member 146 is mounted a locking plate 112 mounted onsprings 150 arranged to normally hold the plate in the position shown.The locking plate 112 is provided with an aperture 151 through which thecam member 146 passes, the right hand edge 152 of the aperture beinground or beveled so as to have easy cam action with the cam projection113 on the member 146. This cam member 113 is arranged, upon downwardmovement, to throw the locking plate 112 over to the right against thetension of the spring 150 until the cam member 113 passes below the edge152 whercupon the plate moves back bringing the edge 152 over the topedge of the cam 113 thus preventing upward movement of the button 105beyond this position, the button 105 and cam member 146 being tensionedupwardly by the compression spring 107 arranged to engage the stem 145through the cross pin 153, at its upper end and to bear against the basemember 143 at its lower end. As the button 105 is locked only againstthe upward movement, it is free to be pushed further downward to operatethe spring 149 and to return out of engagement therewith withoutpermitting the contacts 109110111 to become separated. To release thebutton 105 and permit it to return to its normal position, the off ordisconnect button 106 is provided which also has bearing in the top ofplate 141 and base 143 through its key stem 154 and guide stem 155 andis normally held in the lease the ke 105 under tension of the spring.means 107. It wi 1 thus be seen that in operation when the button 105is pushed down half way it. will become locked against further upwardmovement and maintain the contacts 109110-111 closed during furtherdownward and upward movements of the cam member 146 below this halfposition which latter downward and upward movement will effect anopening and closing of the contacts 114, and that when the finger of theoperator is removed from the button 105 it will remain locked in thehalf osit-ion leaving all the contacts closed until the release button106 is depressed permitting the button 105 to return to the normalposition shown and permit the contacts 109-110-111 to assume the opennormal position shown.

While I have herein shown and described certain specific embodiments ofmy invention for the sake of disclosure, it is to be understood that theinvention is not limited to such specific, embodiments but contemplatesall such modifications and variants thereof as fairly fall within thescope of the appended claims.

For example, while it is referable to use the separate contacts 114 i 3and 4) for selecting or signalin it will e obvious that these contactsmay be omitted and the line circuit opened and closed after the button105 is locked down, by the contacts 109110-111, by providing adepression 148 in the member 146 just above the cam surface 147 intowhich the sprin 109 would move upon complete downwar movement of thebutton, as shown in Fig. 5.

What I claim is:

1. A key set comprising a set of two normally open pairs of contacts, anormally closed pair of contacts in series with said normall opencontacts, unitary actuating or all said contacts arranged upon partialmovement to close said normally open against the contacts but uponfurther movement to open said normally closed contacts, tension meansarranged to normally hold the actuating means in a normal position topermit said contacts to assume normal position, locking means operableupon an operating movement of the actuating means to lock the sameagainst return movement from the partial movement position to normal,but permitting movement between the partial position and full movementposition, and means for releasing said locking means.

2. A key set for controlling a signaling and a. communication circuit,comprising a set of contacts normally maintaining all the circuits open,a set of signaling contacts in series with the first set, and normallymaintaining the signaling circuit closed, actuating means for saidcontacts adapted in partial movement to close the communication contactsand thereafter maintain them closed, in further or full movement to openthe signaling contacts, tension means arranged to normally hold theactuating means in a position to permit said contacts to assume normalposition, locking means operable upon an operating movement of theactuating means .to lock the same against return movement from thepartial movement position to normal, but permitting movement between thepartial position and full movement position, and means for releasingsaid locking means.

3. A key'set for effecting communication with a multiconductor telephonecircuit, and for signaling thereover, comprising circuit closingcontacts forming terminals of said conductors, respectively, and unitaryself contained actuating means therefor movable into three positions,opening the circuit in the first or'normal position, closing the-same inintermediate or partial movement position, and again opening the samefor signaling in the third or full movement position, tension meansarranged to hold the actuating means in normal position, locking meansoperable upon an operating movement of the actuating means to lock thesame against return movement from the partial movement position tonormal, but permitting movement between the partial position and fullmovement position, and means for releasing said-locking means.

In testimony whereof I hereunto afiix my signature.

EDWARD E. CLEMENT.

